Various types of antibacterial members have been developed and turned into products to reduce microbes in the environment because of increased consumers' consciousness of hygiene. In general, antibacterial members used for interior members in houses or vehicles contain antibacterial materials such as silver and zinc (for example, refer to Patent Literatures 1 and 2). However, silver and zinc have a problem of costs or biological toxicity.
Accordingly, attempts are being made to use titanium oxide, which is cheap, abundant, and less ecotoxic, as an antibacterial material (for example, refer to Patent Literature 3). Titanium oxide is photocatalytically active, and the antibacterial action using the photocatalytic activity thereof is attracting attention.
Herein, titanium oxide is white powder as often used in pigment of white paint. To use antibacterial members in various applications, some techniques are required to ensure the transparency thereof even when the antibacterial members include titanium oxide. Specifically, titanium oxide needs to be microparticulated using bottom-up synthesis or various dispersion techniques.